Download and place the file(s) in a directory called WhosOnline in your extensions/ folder.

Add the following code at the bottom of your LocalSettings.php:

wfLoadExtension('WhosOnline');

Run the update script which will automatically create the necessary database tables that this extension needs.

If you want anonymous users IP addresses shown, add:

$wgWhosOnlineShowAnons=true;

to LocalSettings.phpafter the above statement. Default is not to show them, for privacy reasons.

YDone - Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

To users running MediaWiki 1.24 or earlier:

The instructions above describe the new way of installing extensions using wfLoadExtension(), since MediaWiki 1.25. If you need to install this extension in earlier versions, instead of wfLoadExtension( 'WhosOnline' );, you need to use:

Users who login after the extension is installed can be seen at Special:WhosOnline. Refresh the page if it is blank. As of version 1.3.1 it is possible to include the contents of the special page into a page: {{:Special:WhosOnline}}. If you use {{:Special:WhosOnline/10/shownav}} it will only show 10 users and will have the navigation controls.